It is apparent when it comes to the need to send both analog video and audio data over a distance; one cable is better than two cables in terms of cost and complexity. Various methods and apparatuses have been proposed to reduce the cost and complexity of sending both analog and video signal by transmission over a single coaxial cable. To avoid interference between the analog video and audio data on a single cable, there are potentially two ways to get the required separation. Frequency multiplexing audio data and video data and transmitting each data signal over distinct non-overlapping frequency band is known. Interleaving an audio signal and a video signal in the time domain thereby having the video and audio data present in the signal at different times without interfering with each other is known. Interleaving audio data when active video is not present during the video-blanking is also known. However, current signaling protocols are complex and require intensive calculation for interleaving audio data in with video data.
For example, U.S. application Ser. No. 14/442,803 of Zhejiang Dahua Technology Co., Ltd. discloses a method of and apparatus for transmitting a high-definition video signal to address the problem in the prior art, i.e., the cost and complexity of transmitting analog and audio over a distance using a single coaxial cable. In particular, the '803 applications proposed to buffer audio data by calculating an audio duration for every each row in the video frame that audio data is superimposed. However, the proposed method of the '803 application creates the need to for calculating and storing an audio duration size in every active row of video data. Doing so requires storing and buffering audio durations that are not small and require burdensome buffering and storage requirements, which complicates the coding scheme. The exemplary implementations described herein do not require calculating the number of audio samples to be stored in the buffer and transmitted per frame basis and employs much smaller buffer, reducing cost of manufacture and operating power requirements.
Accordingly, there remains a need in the art for a solution that addresses the problems discussed above among others.